This invention relates to an intelligent power assisted manual manipulator controllable by operator inputs from an operator for moving an object.
Manipulators are used to reorient or move heavy objects from one location to another. One type of manipulator is a powered manipulator that utilizes overhead rails or a bridge gantry with a carriage movably supported thereon. An arm is pivotally attached to the carriage to lift the objects from overhead. It is desirable to have the operator as close to the object as possible to make movement of the object more intuitive as if the operator was actually lifting and moving the object. To this end, it is desirable to utilize power assisted manual manipulators. Operator safety is an important consideration when designing power assisted devices and determining appropriate power sources for moving the objects because the weight of the objects or power source may produce high forces capable of seriously injuring the operator. However, a power assisted manual manipulator must also provide adequate operator safety. As a result, the devices typically are either manipulated using either only physical force imparted on the device by an operator or by remote actuation of hydraulic or pneumatic cylinders to avoid operator injury. Relying on only the operator""s physical strength limits the weight of the objects to be moved and creates ergonomic problems. Utilizing hydraulic or pneumatic power sources provides only rough control of the device""s movements making remote actuation difficult and power assisted manual operation of the device unsafe. Also, lack of a direct, intuitive human interface requires a lengthy training period before an operator can safely and effectively operate the manipulator.
Manipulators utilizing carriages supported on overhead rails typically are designed to achieve precision alignment between the carriage and the rail. To this end, carriages having rollers supported on precision machined hardened ways have been used. However, achieving precision alignment in this manner is difficult and costly. Further, manipulators often utilize hydraulic or pneumatic loads, or weights to both move the object and to counterbalance the weight of heavy objects and the weight of the lift mechanism. These balancers are suited for counterbalancing the weight of one object and are not well suited to balancing objects of different weights or do not provide the necessary control of the object. Therefore, what is needed is an intelligent power assisted manual manipulator that is safe for an operator to use, cost effective, and that may accommodate objects of different weights while providing the needed control of the object.
The present invention provides an intelligent power assisted manual manipulator controllable by operator inputs from an operator for moving an object. The manipulator includes a movable base supporting a lift mechanism for moving the object. The manipulator also includes at least one servomotor for actuating the lift mechanism and moving the object. An operator control mechanism for receiving the operator inputs is supported on the lift mechanism. A plurality of force sensors are disposed between the operator control mechanism and the lift mechanism for sensing said operator inputs and actuating at least one of servomotors.
According to an another aspect of the present invention, the movable base includes an overhead rail defining a generally horizontal first axis and a carriage supported on the overhead rail and movable along the first axis. The lift mechanism includes a turret assembly supported on the carriage having a generally vertical second axis, and a generally horizontal third axis. A main arm extends from the turret and is rotatable about the third axis. Since the main arm is attached to the turret it is rotatable about the second axis with the turret. An attachment interface is supported by the main arm and adapted to support the object, the attachment interface having a fifth axis about which the attachment interface is rotatable.
According to yet another aspect of the present invention, the manipulator is also adapted for lifting different objects having different weights. The manipulator includes a support member and an arm extending from the support member at a pivotal connection. The pivotal connection defines a generally horizontal axis with the arm rotatable about the axis in a generally vertical plane. The arm has a portion opposite the pivotal connection adapted to support the object. A lift servomotor is adapted to support the different weights including the weight of the arm itself, and a motion servomotor is adapted to produce a movement of the arm by drivingly rotating the arm about the axis.
According to still another aspect of the present invention, the carriage has first and second elongated portions in opposing generally horizontal planes and third and fourth elongated portions in generally vertical planes. First, second, third, and fourth ways are disposed along the first, second, third, and fourth elongated portions, respectively, for providing a bearing surface. At least two first, second, third, and fourth rollers are supported on the carriage and are in rolling engagement with the first, second, third, and fourth ways, respectively.
Accordingly, the above aspects of the present invention provide an intelligent power assisted manual manipulator that is safe for an operator to use and that may accommodate objects of different weights.